1. Field of the Invention
The present invention relates to an accumulator applied to a vapour-compression type refrigerating machine. The present invention is effectively used for an ultra-critical pressure type refrigerating machine in which the pressure of refrigerant (discharge pressure of a compressor) on the high pressure side becomes higher than the critical pressure of refrigerant.
2. Description of the Related Art
In a vapour-compression type refrigerating machine, which will be referred to as a refrigerating machine hereinafter, for example, as described in Japanese Unexamined Patent Publication No. 10-19421, when heat is exchanged between refrigerant on the high pressure side, which is cooled, and refrigerant on the low pressure side which is decompressed by a pressure reducing device and sucked into a compressor, it is possible to prevent liquid-phase refrigerant from being sucked into a compressor while the enthalpy of refrigerant flowing into an evaporator (heat exchanger on the low pressure side) is being decreased. Therefore, it is possible to protect the compressor while the efficiency (coefficient of performance) of the refrigerating machine is being enhanced.
In this connection, in the refrigerating machine disclosed in the above patent publication, an internal heat exchanger, which exchanges heat between the refrigerant on the high pressure side and that on the low pressure side, is housed in an accumulator tank so that the number of parts can be reduced. However, it is necessary to provide a refrigerant pipe to connect the pressure reducing device with the internal heat exchanger and also it is necessary to provide parts for piping such as packing and so forth. Further, it is necessary to conduct connection work for connecting these parts for piping. Accordingly, it is difficult to reduce the manufacturing cost of the refrigerating machine.
In view of the above problems, the present invention has been accomplished. It is an object of the present invention to provide an accumulator capable of reducing the number of parts of a refrigerating machine.
In order to accomplish the above object, an accumulator module of the present invention comprises: an accumulator tank (140) for separating refrigerant into gas-phase refrigerant and liquid-phase refrigerant and storing redundant refrigerant therein, the thus separated gas-phase refrigerant flowing out from the accumulator tank (140) onto the suction side of the compressor (110); a pressure reducing device (161a) for decompressing refrigerant on the high pressure side which is compressed by the compressor (110) and cooled after that; and an internal heat exchanger (150) for conducting heat exchange on the refrigerant on the low pressure side which is decompressed by the pressure reducing device (161a), before it is sucked into the compressor (110), wherein the pressure reducing device (161a) is fixed to the accumulator tank (140), and the internal heat exchanger (150) is housed in the accumulator tank (140).
Due to the foregoing, it is possible to eliminate parts of piping to connect the pressure reducing device (161a) with the internal heat exchanger (150). Therefore, it is possible to reduce the number of parts of a vapour-compression type refrigerating machine. As a result, it is possible to reduce the time necessary for assembling the refrigerating machine.
In this connection, when the refrigerant is decompressed by the pressure reducing device (161a), a valve body provided in the pressure reducing device (161a) tends to vibrate. Therefore, noise (vibration) tends to be generated. However, according to the present invention, the accumulator tank (140), the first pressure reducing device (161a) and the internal heat exchanger (150) are integrated into one body. Accordingly, the mass of the vibration system of the pressure reducing device (161a) including the accumulator tank (140) and the internal heat exchanger (150) is increased. Therefore, even when the valve body is vibrated, it is difficult for other portions to vibrate. For the above reasons, it becomes possible to reduce the occurrence of noise (vibration) generated when the refrigerant is decompressed by the pressure reducing device (161a).
In this connection, reference numerals in the parentheses in the above means correspond to the specific means of the embodiment described later.